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(No Model.) Y l G. W. FOSTER. Telephone.

No. 237,379. Patented Feb. 8,1881.

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Y Effi/awk @a y y UNITED STATES PATENT OFFICE.

GAY vv. FOSTER, oF CHICAGO, ILLINOIS, ASSIGNOE To THE FOSTER MAGNET TELEPHONE COMPANY, OF SAME PLAGE.

TELEPHONE.

SPECIFICATION' forming part of Letters Patent No. 237,379, dated lFebruary 8, 1881. Application lerl September 10, 1880. (No model.)

-To all 'whom it may concern:

Be it known e that I, GAY W. FOSTER, of Chicago, in the countyot` Cook and State of Illinois, have invented a new and useful Improvement in Telephones; and I do hereby declare that the following is a full, clear, and exact description of the same.

The objects ot' my invention are to remove all liability of twisting or breaking oft' of the connections on the telephone-cords; also, to secure a magnet in the telephone in such a manner as to allow it to be easily adjusted to or from the diaphragm.

The construction and arrangement of parts are as hereinafter described, reference being had to the accompanying drawings, forming a part of this specification, in Which- Figure lis an exterior plan view of my telephone, and Fig. 2 is a central longitudinal section of the same.

A indicates a screw-magnet-that is to say, a magnet having a thread cuton the rear end of it. On the end of this magnet nearest the diaphragm His au induction-coil, B, connected with the ground-wire and the main line, for the purpose of inducing a current of electricity over the main line.

C represents a cylindrical hole drilled into the body of the telephone, for the purpose of receiving and firmly holding the magnet A in any desired distance from the diaphragm H, the rear end of the cylindrical hole being drilled somewhat smaller than the opposite end of the same, causing a shoulder to be made upon its surface for the purpose of freely admitting the magnet A until the screw end ofsaid magnet enters the screw-threaded portion of the hole, when it becomes necessary to screw the end of the magnet into the small end of the cylindrical hole, the thread on thel magnet cutting its way into the outer surface of the cylindrical hole, for the purpose of holding the said magnet iirmly in its position.

D indicates a notch cut in the end of thev magnet A, for the purpose of' allowing a firm gripe to be made on the end ofthe magnet with a pair of nippers, or otherwise, for the purpose of rotating the magnet to the right or left to `adjustit to or from the diaphragm by means of the thread on the magnet A and the corre- 5o sponding thread in the cylindrical hole O. Y

E represents cylindrical holes drilled through on two opposite sides of the handle of the teleph one, forthe purpose of passing the telephonecords through the handle to the binding-posts F F, causing two distinct curves in the telephone-cord, thereby removing all strain or tension from the binding-post or point of cord, thus removing all liability ot' breaking oft' the points of cord or loosening the binding-posts 6o from their position.

F F represent the binding-posts, for the purpose of connecting the telephone-cords with the induction-coil on the magnet A by means of soldering the wire from the coil to the post and fastening the end of cord in the post with a screw, for the purpose of completing the circuit through the telephone, the position ofthe binding-posts being horizontal, being screwed into the opposite sides of the telephone to give 7o easy access to the metal point ofthe telephonecord. A

G represents the telephone-cord as connected, when ready for use. Y

Hrepresents a metal diaphragm resting on a narrow flexible rubber ring, t', Fig. 5, which is placed within the mouth-piece to insulate the diaphragm from the wood body ot' the mouth-piece, and at the same time making an air-chamber between the diaphragm and the 8o mouth-piece, thereby increasing the vibration of the diaphragm.

Fig. 3 represents a modification of Fio. 2, for the purpose of dispensing with the bindingposts F F and reducing the cost of the tele- 85 phone, at the Same time making less work in constructing it.

f represents the metallic end of a telephonecord, which is set in a cylindrical hole on the two opposite sides of the telephone-body, said 9o hole having a shoulder in it, making one-halt' the length of the hole just large enough to receive the small end of the telephone-cord I, and the other halt' being larger, so as to admit the large portion of the metal point f, the small point being fastened in a nut, J, by means of a thread cut on the outer surface ot the point, and a corresponding thread on the inner surface of the nut, the Wire ends of the induction-coil being fastened around the point under the nut, completing the circuit through the instrument.

Fig. 4 represents a sectional View of' the mouth-piece, showing the position of the diaphragm and the manner of insulating it from the Wood.

H represents the diaphragm lying dat on the surface of a rubber ring, fi, thus forming an air-chamber between the diaphragm and the openin g of the month-piece and insulating it from the body of the mouth-piece, for the purpose of increasing the vibration of the diaphragm.

Fig. 5 is a plan View of the rubber ring used to insulate the diaphragm from the body of the mouth-piece, for the purpose of increasing the vibration of the diaphragm.

What I claim is- 1. In a telephone, the combination of a permanent magnet, screw-threaded at one end and notched at the other end, with a telephone handle or case provided with an axial recess or hole reduced and screw-threaded at its rear end for the reception of said magnet, substantially as shown and described.

2. A telephone handle or case provided with an axial recess for the reception of a magnet, and with two holes parallel to said recess arranged to receive and protect the conductingwres, and with two holes formed at an angle to the magnet 'and in the same plane with the parallel holes, for the purpose of connecting the terminals of the helix with the conductingwires GAY W. FOSTER. NVitnesses:

W. DMORTON, Jr., MILLARD R. PoWERs. 

